#include <Eigen/Dense>
#include <iostream>

using namespace std;
using namespace Eigen;

int
main()
{
	Matrix2d A;
	A << 2, 1, 2, 0.9999999999;
	FullPivLU<Matrix2d> lu(A);
	cout << "By default, the rank of A is found to be " << lu.rank() << endl;
	lu.setThreshold(1e-5);
	cout << "With threshold 1e-5, the rank of A is found to be " << lu.rank() << endl;
}
